Digital background calibration of subsampling time-interleaved ADCs

A technique for the digital background calibration of subsampling time-interleaved analog-to-digital converters is proposed. The technique corrects the errors due to gain, offset and timing mismatches among the time-interleaved channels by estimating and nulling the errors with respect to a reference channel through least mean squares loops. Wideband undersampled differentiator filters are exploited thus enabling digital background calibration of timing skews even with wideband input signals outside the first Nyquist band.